Thio-urea compound and process of making same.



UNiTnn STATES PATENT OFFICE.

ADOLF ISRAEL AND RICHARD KOTIIE, OF ELBERFELD, GERMANY, ASSIGN- ORS TOFARBENFABRIKEN OF ELBERFELD (30., OF NE\V YORK, N. Y.

THIO-UREA COMPOUND AND PROCESS OF MAKING SAME.

SEES .IGATION forming part of Letters Patent No. 675,631, dated June 4,1901.

Application filed December 31, 1900.

To all whom it may concern:

Be it known that we, ADOLF ISRAEL and RICHARD KOTHE,doct0rs ofphilosophy, chemists, (assignors to the FARBENFABRIKEN or ELBERFELDCOMPANY, of New York,) residing at Elberfeld, Germany, have invented anew and useful Improvement in ThioUrea Compounds and Processes of MakingSame; and we hereby declare the following to be a clear and exactdescription of our invention.

Our invention relates to the production of anew thio-urea compoundderived from amidonaphthol sulfonic acids, being an alkaline salt of anacid having the following formula:

The process for producing this body consists in heating an equimolecularmixture of betaamido alpha naphthol beta sulfonic acid and alpha-amido-alpha -naphthol-beta -sulfonic acid with carbon bisulfid (CS andsulfur in a neutral or slightly-alkaline solution. A condensation of thetwo above-named amidonaphthol sulfonic acids with one molecule of carbonbisulfid takes place under evolution of one molecule of sulfuretedhydrogen, the above-defined thio-urea derivative being thus formedaccording to the following equation:

l l l 2 i l l W i $erial No. 41,628. (No specimens.)

l i L 1 so..n+sn.

i l l on v The new thio-urea derivative thus obtained may be employedforihe man u factu re of valuable azo dyestuifs. i

In carrying out our new process practically we can proceed as follows,the parts being by weight: To a solution of twelve parts of beta-amido-alpha -naphthol-heta sulfonic acid and twelve parts of alpha-amido-alpha 6O naphthol-beta -sulfonic acid in about from two hundredto three hundred parts of water, to which so much sodium carbonate hasbeen added as to render it slightly alkaline, we add two hundred tothree hundred parts 65 of ethylic alcohol from twenty to twenty-fiveparts of carbon bisulfid, and from 0.4 to 0.5 parts of powdered sulfur.The mixture thus obtained is boiled in a vessel provided with areflux-condenser until the evolution of sul- 7o fureted hydrogen ceases.After the alcohol and the superfluous carbon bisuliid have beendistilled off the reaction mixture is filtered in order to remove thesulfur which has been precipitated. The filtrate is then 75 acidulatedby means of hydrochloric acid and the thio-urea derivative isprecipitated from the acid solution by the addition of common salt. Forfurther purification it is extracted with water, filtered, and then pre3O cipitated again by the addition of common salt. The pure sodium saltof the new body thus obtained crystallizes from water containing commonsalt in the shape of whitish flakes, which are readily soluble in coldand 5 very readily in hot water and soluble with difficulty in alcohol.The barium salt represents a grayish powder which is soluble in cold andreadily soluble in hot water. The calcium salt is a grayish powder whichis very readily soluble in hot and less soluble in cold water, Thesesalts are prepared by the addition of solutions of barium chlorid (BaOlor of calcium chlorid (CaCl to watery solutions of the sodium salt ofthe said thio-urea derivative. On boiling the thiourea derivative withthe twentyfold quantity of hydrochloricacid of twenty per cent. itdissolves, and after boiling for some time beta -amido alpha naphtholbeta -sulfonic acid and alpha -amido-alpha -naph thol-beta; sulfonicacid are regenerated. The new thiourea derivative is capable ofcombining with one and likewise with two molecules of diazo compounds,thus to rnishing valuable-azo dye Having now described our invention andin what manner the same is to be performed, What we claim as new, anddesire to secure by Letters Patent, is-

1. The process for producing a new thio 2. The herein-described new thiourea derivative which in the form of the free acid has the followingformula:

and in the form of the sodium salt consists of whitish flakes, beingcapable of combining with one and likewise with two molecules of diazocompounds, being readily soluble in cold, very readily soluble in hotWater, and which on boiling with the twentyfold quantity of hydrochloricacid of twenty per cent. dissolves and after some time-beta -amidoalpha-naphthol-beta- -sulfonic acid and alpha -amido alpha naphthol betasulfonic acid are regenerated, substantially as hereinbefore described.a

In testimony whereof we have signed our names in the presence of twosubscribing witnesses.

ADOLF ISRAEL. RICHARD KOTHE.

Witnesses:

. OTTO KoNIe,

J. A. RITTERSHAUS.

